hana/test/range/unpack.cpp
2017-01-07 14:14:18 -08:00

46 lines
1.5 KiB
C++

// Copyright Louis Dionne 2013-2017
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#include <boost/hana/assert.hpp>
#include <boost/hana/core/make.hpp>
#include <boost/hana/core/tag_of.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/integral_constant.hpp>
#include <boost/hana/range.hpp>
#include <boost/hana/unpack.hpp>
#include <laws/base.hpp>
#include <type_traits>
namespace hana = boost::hana;
int main() {
hana::test::_injection<0> f{};
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<0>), f),
f()
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<1>), f),
f(hana::int_c<0>)
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<2>), f),
f(hana::int_c<0>, hana::int_c<1>)
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<3>), f),
f(hana::int_c<0>, hana::int_c<1>, hana::int_c<2>)
));
// Previously, we would only unpack with `std::size_t`s. Make
// sure this does not happen.
hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<1>), [](auto x) {
using T = hana::tag_of_t<decltype(x)>;
static_assert(std::is_same<typename T::value_type, int>{}, "");
});
}